Gas lighter

ABSTRACT

Gas lighter comprising a reservoir, for containing a fuel, the reservoir having an upper wall through which a well and a gas-dispensing device passes. The gas-dispensing device includes at least one tubular element arranged in the well. The tubular element including at least one snap-fitting member designed to cooperate with a retaining element secured to the upper wall of the reservoir in the well when the tubular element is assembled with the reservoir.

FIELD OF THE INVENTION

[0001] The present invention relates to gas lighters.

BACKGROUND OF THE INVENTION

[0002] More particularly, the invention relates to a gas lighter comprising a reservoir, to contain a fuel, the reservoir having an upper wall through which a well, and a gas-dispensing device passes, the gas-dispensing device includes at least one tubular element arranged in the well.

[0003] Generally, the tubular element of the dispensing device is installed into a well by screwing a threaded ring into a tapped upper part of the well, as depicted in FIG. 1 of document WO-A01/18452. This type of fitting has the advantage in that it can be used particularly with a reservoir made of an amorphous polymer.

[0004] The above-mentioned amorphous polymers are polymers having chains of monomers disposed in disordered or random manner, unlike semi-crystalline or crystalline polymers, in which the chains are disposed uniformly. Certain amorphous polymers offer advantages for making fuel reservoirs for lighters, with particular examples worth mentioning being the categories of SANs (styrene acrylonitriles) and ABSs (acrylonitrile butadiene styrenes). Certain amorphous polymers are also transparent, which makes it possible to see the level of liquid fuel remaining in the reservoir. Amorphous polymers are also generally less expensive and easier to use than semi-crystalline polymers.

[0005] However, these amorphous polymers are relatively brittle at ambient temperature because their elongation at the elastic limit is small, generally less than 5%. Fitting the tubular element using a threaded ring creates practically no tensile stress in the wall of the well, unlike force-fitting techniques previously known, thus avoiding the appearance of microcracks through which gas may escape.

[0006] However, using a threaded ring requires the use of relatively complex molds which lengthen the de-molding operations. In addition, the operation of screwing the threaded ring into the well is a relatively difficult and lengthy process to perform in an automated manufacturing process thus increasing the time needed for assembling the lighters. These disadvantages mean that the cost of manufacture for mass production is significantly increased.

SUMMARY OF THE INVENTION

[0007] The present invention provides a gas lighter that provides a simplified fitting for the tubular element into the well, while at the same time affording a good seal, which is compatible with the use of amorphous polymers.

[0008] To this end, a lighter having a tubular element including at least one snap-fitting member designed to cooperate with a retaining element formed on the upper wall of the reservoir is provided.

[0009] By virtue of this arrangement, the tubular element and the upper wall of the reservoir preferably have relatively smooth walls and thus are easier to manufacture since the snap-fitting element does not have any screw threads.

[0010] Furthermore, fitting the dispensing device onto the reservoir is also simpler and quicker because all that is required is for the tubular element to be forced into the well until the snap-fitting member engages the retaining element.

[0011] In addition, it is optionally possible to use any of the following provisions singularly or in combination:

[0012] an annular seal is arranged between the upper wall of the reservoir in the well and the tubular element to improve sealing. More preferably, the annular seal is arranged between a radially external rim formed on the tubular element and a radially internal rim formed on the upper wall;

[0013] the tubular element has a first axial distance H₁ measured along its longitudinal axis. The first axial distance H₁ extending from the radially external rim to the point of contact of the snap-fitting members with the retaining element. The well has a second axial distance H₂ extending from the radially internal rim to the point of contact of the snap-fitting members with the retaining element. The first axial distance H₁ and the second axial distance H₂ being chosen to exert a pre-determined pressure on the annular seal which provides improved sealing without giving rise to significant tensile stresses in the wall of the well;

[0014] the retaining element is preferably formed on the lower portion of the interior face of the upper wall of the reservoir;

[0015] the snap-fitting member is preferably arranged in the lower portion of the tubular element; thus making it generally non-accessible to users who may desire, for whatever reason, to dismantle the tubular element from the lighter;

[0016] the snap-fitting member includes a tab having a nib, which is directed radially outwards and has a transverse face. The tab has an elasticity which allows the nib to deform inwards as the tubular element is forced into the well, while permitting the nib to return to its regular position when the tubular element reaches its assembled position, thus permitting the transverse face of the nib to bear against the retaining element.

[0017] the tubular element includes an inner tube, preferably made of metal, the inner tube preferably having a microporous membrane located at the lower end of inner tube. The microporous membrane ensuring a roughly constant gas flow rate;

[0018] the upper end of the tubular element comprising a radially internal rim defining an opening through which passes an outlet duct of a valve which can move along the axis of the tubular element, thus permitting the valve to move from an at rest position, whereby preferably the valve is closed to an in-use position, whereby preferably the valve is opened. Preferably a compression spring is arranged between the radially internal rim and the valve so as to bias the valve closed;

[0019] the reservoir is preferably manufactured from an amorphous polymer. More preferably, the reservoir is manufactured from SANs or ABSs;

[0020] the tubular element is preferably manufactured from a semi-crystalline polymer.

[0021] Other features and advantages of the invention will become apparent to those skill in the art during the description which will follow, given by way of non-limiting example, with reference to the appended drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0022]FIG. 1 is a vertical cross sectional view of an embodiment of a top portion of a lighter; and

[0023]FIG. 2 is a simplified vertical cross sectional view of an alternate embodiment of a gas dispensing device.

DETAILED DESCRIPTION OF THE INVENTION

[0024] In the various figures, the same references are used to designate identical or similar elements.

[0025] For purposes of promoting an understanding of the principles of the present invention, reference will now be made to an exemplary, non-limiting embodiment illustrated in FIG. 1. As shown, the gas lighter 1 comprises a reservoir 2 intended to contain a fuel under pressure and, partially, in liquid phase, such as isobutene.

[0026] In the embodiment of the lighter shown, the reservoir 2 is formed of a bowl 3, the bowl 3 preferably being U-shaped in cross section, and having a bottom wall, not visible in FIG. 1, and an annular side wall that extends upwards from the bottom wall to an upper end 4.

[0027] The upper end 4 may be closed off by an upper wall 5 which, in the example depicted, may be a separate part fixed to the bowl 3 by any method known in the art including, but not limited to bonding, gluing, welding, friction or press fit, etc. Alternatively, the upper wall 5 may be manufactured as an integral part with the bowl 3.

[0028] The reservoir 2 is preferably manufactured from at least one rigid amorphous polymer material, including, for example, from ABSs (acrylonitrile butadiene styrenes), SANs (styrene acrylonitriles), etc. Alternatively, by way of example, the bowl 3 may be manufactured from SAN, while the upper wall 5 may be manufactured from ABS, and vice versa, it being possible, in known manner, to bond these materials together, for example by ultrasonic sealing, bonding, ultrasonic welding, gluing, etc.

[0029] As previously stated, the advantage of such amorphous polymers is that they are relatively inexpensive and easy to implement, process, manufacture, and form parts from. In addition, the amorphous polymer material, such as SAN, may be transparent, making it possible for the gas lighter user to see the level of liquid fuel remaining in the reservoir.

[0030] Other amorphous-type polymers may be used, provided that their mechanical and chemical properties are compatible with them being used as a gas lighter.

[0031] The upper wall 5 of the reservoir may further have a well 6, that in the example shown extends along a vertical axis Z and which advantageously may be in the shape of a cylinder that is circularly symmetrical.

[0032] The well 6, generally speaking, is capable of receiving a gas dispensing device 10 that is actuated by an operating device 11 carried by the head 12 of the lighter, which overlies the reservoir 2. In the embodiment depicted, the head 12 preferably is retained against the upper wall 5 of the reservoir by catches 20 (i.e., studs) on the head 12 that cooperate by snap-fitting or clipping with complementary catches 21 molded in the upper wall 5 of the reservoir 2.

[0033] The head 2 may also form a support for fitting an ignition device 14 and a windshield 13, the windshield 13 forming a screen or shield against the wind or draft.

[0034] The ignition device 14, which are generally widely known in the art, may comprise, for example, a spark wheel 15 and a flint 16 held pressed against the spark wheel 15 by a spring 17 received in a circular cavity 18 in the head 12. A complementary cavity 19 is formed in the upper wall 5 of the reservoir 2 to accommodate the cavity 18 of the head 12. However, it is of course possible to use other types of ignition devices, such as a piezoelectric device, etc.

[0035] The dispensing device 10 generally includes a tubular element 22, which preferably is in the shape of a cylinder that is circularly symmetrical for engaging the upper wall 5 of the reservoir 2 in the well 6. Preferably, the tubular element 22 may include an inner tube 23, which is made of metal. The tubular element 22 preferably is made of a semicrystalline polymer such as POM (polyoxymethylene) or nylon-6,6. These semi-crystalline polymers generally have a high strength, thus permitting the inner tube 23 to be force-fitted into the tubular elements 22, thus sealing and immobilizing the inner tube 23 in the tubular element 22.

[0036] The lower part 24 of the inner tube 23 preferably has a regulating device for regulating the gas flow rate, which regulating device may be, for example, a microporous membrane 25. This microporous membrane 25 preferably includes a film of polypropylene stretched uniaxially and having pores of elongate shape, as described in U.S. Pat. No. 4,496,309. The microporous membrane 25 preferably is held against an interior shoulder 23 a of the inner tube 23, the shoulder 23 a being formed in the vicinity of the lower end 24 of the inner tube 23. Thus enabling the microporous membrane 25 to cover an orifice 26 formed in the center of the shoulder 23 a. The microporous membrane 25 is preferably pressed against the bottom face of the shoulder 23 a by a rigid ring 27, which is itself retained at the bottom of the inner tube 23 by crimping the lower end 24 of the inner tube 23.

[0037] The tubular element 22 may comprise two snap-fitting members 28, 29 designed to cooperate with a retaining element 30 to secure the tubular element 22 with the upper wall 5 of the reservoir 2 in the well 6. Thus, the tubular element 22 and the upper wall 5 are assembled without any screw threads making the lighter particularly easy to assemble since all that is required for the tubular element 22 to engage the upper wall 5 of the reservoir 2 is for the tubular element 22 to be forced into the well 6 in between the upper wall 5 until the snap-fitting members 28, 29 engage the retaining elements 30. Furthermore, since the tubular element 22 and the upper wall 5 of the reservoir do not have any screw threads, they can be manufactured using molds which allow higher production rates.

[0038] The snap-fitting members 28, 29 are preferably arranged in the lower portion 22 a of the tubular element 22, thus making them generally non-accessible to users. Thus, increasing the safety of the lighters by decreasing the likelihood that a user, for whatever reason, would dismantle the tubular element 22 from the lighter.

[0039] The retaining element 30 is preferably formed on the lower portion of the interior face 5 a of the upper wall 5 of the reservoir 2.

[0040] It should be noted, however, that it is of course possible for the quantity of snap-fitting members to vary.

[0041] Preferably, the upper wall 5 of the reservoir 2 in the well 6 and the tubular element 22 have smooth walls which are in contact with each other over a relatively long length thus providing a proper seal between the reservoir 2 and the gas dispensing device 10. More preferably, when the reservoir is manufactured from an amorphous polymer, such as SAN or ABS, the diameter of the tubular element 22 does not exceed the diameter of the well 6.

[0042] To permit assembly with a pre-filled reservoir 2, preferably, the well 6 includes a diaphragm (not shown), to reduce leakage of fuel. The diaphragm being broken upon entry of the tubular element 22 into the well 6.

[0043] An annular seal 31 is preferably arranged between the upper wall 5 and the tubular element 22 in the well 6. More preferably, the annular seal 31 is arranged between a radially external rim 32 formed on the tubular element 22 and a radially internal rim 33 formed on the upper wall 5.

[0044] Furthermore, preferably the tubular element 22 has a first axial distance H₁ measured along its longitudinal axis Z. The first axial distance H₁ extending from the radially external rim 32 to the point of contact of the snap-fitting members 28, 29 with the retaining element 30. The well 6 having a second axial distance H₂ extending from the radially internal rim 33 to the point of contact of the snap-fitting members 28, 29 with the retaining element 30. Advantageously, the first and second distances (H₁, H₂) are chosen so that a pre-determined but not excessive pressure is exerted on the annular seal 31 thus ensuring proper sealing.

[0045] In contrast with prior art devices, which as stated above requires a threaded ring, the fitting between the tubular element 22 and the upper wall 5 allows the pressure exerted on the seal to be set more precisely.

[0046] As shown, each snap-fitting member 28, 29 generally includes a tab 35 extending from the lower end of the tubular element 22 in the longitudinal direction Z. The tab ending in a nib 36, which is directed radially outwards and having a transverse face 37 directed towards the upper end of the tubular element 22. The tab 35 has a radial elasticity which allows the nib 36 to deform inwards as the tubular element 22 is forced into the well 6 in between the upper wall 5. The tab's elasticity thereafter permits the nib 36 to return to its position when the tubular element 22 reaches its assembled position, thus permitting the transverse face 37 of the nib 36 to bear against the retaining element 30.

[0047] As best shown in FIG. 2, the cross section of the tabs 35 generally forms two diametrically opposed circular arcs.

[0048] As further shown in FIG. 1, the dispensing device 10 preferably includes a valve 40 having a gas outlet duct 41 opening near the ignition means 14. The duct 41 preferably includes a shutter 42 located in the lower part of the dispensing device 10. Preferably, the shutter 42 is made from an elastomeric material designed to shut off the gas passage orifice 26 as the duct 41 is move along the longitudinal axis Z of the tubular element 22. Preferably, the duct 41 also contains slots 43 formed near the shutter 42 in order to provide communication with the inside of the inner tube 23.

[0049] Furthermore, the operating device 11 includes a fork 45 mounted to tilt about a pin secured to the head 12. The fork 45 having a first end 46 and a second end 49. The first end 46 cooperates with a lower shoulder 47 and an upper shoulder 48 formed on the upper end of the duct 41 which emerges from the inner tube 23 thus permitting the gas dispensing device 10 to be raised as the user depresses the second end 49 of the fork 45. When the user depresses the second end 49 of the fork 45 raising the duct 41, the valve 40 is opened releasing gas from the reservoir 2.

[0050] Preferably, a compression spring 50 is arranged between the underside of the second end 49 of the fork 45 and the upper wall 5 of the reservoir 2 thus biasing the fork 45 upwards and hence biasing the valve into a closed position when the lighter is not in use.

[0051] In the alternate embodiment depicted in FIG. 2, the upper end 52 of the tubular element 22 may include a radially internal circular rim 53 which defines an opening 54 through which the outlet duct 41 passes. A compression spring 55 is preferably arranged between the circular rim 53 and the lower shoulder 47 of the duct 41, so as to bias the valve closed during non-use. Similar to the operation described above, to open the valve the user simply exerts a downward force on the fork 45 (not depicted in FIG. 2) causing the fork 45 to tilt so that the first end 46 of the fork 45 presses on the upper shoulder 48 of the duct 41 and lifts the duct 41, compressing the spring 55. When the user stops exerting the downward force on the fork 45, the compression spring 55 causes the duct 41 to be returned to its closed position. It will be noted that in this embodiment the spring 50 placed under the second end 49 of the fork 45 is replaced by the spring 55 placed between the circular rim 53 and the lower shoulder of the duct 41, thus the spring 50 beneath the second end 49 of the fork 45 is no longer needed.

[0052] In this embodiment, the dispensing device 10 forms a complete assembly comprising a device for regulating the gas flow rate, which is preferably formed by the microporous membrane 25 as described above, and a valve 40 for controlling the flow rate. The valve 40 has the advantage of being naturally in its closed position thus preventing the escape of gas from the reservoir when not in use. Furthermore, since the dispensing device of this embodiment is installed as a complete assembly, this embodiment further prevents the escape of gas that may occur after the piercing of the diaphragm situated in the well 6 but before the fitting of the valve 40. Aside from the reduction in gas losses, this embodiment also makes it possible to simplify the devices that recuperate gas on the production line.

[0053] The present invention has been described in connection with the preferred embodiments. These embodiments, however, are merely for example and the invention is not restricted thereto. It will be understood by those skilled in the art that other variations and modifications can easily be made within the scope of the invention as defined by the appended claims, thus it is only intended that the present invention be limited by the following claims. 

We claim:
 1. A gas lighter comprising: a reservoir having an upper wall; a well, the well passing through the upper wall; and a gas-dispensing device having at least one tubular element arranged in the well, wherein the tubular element has at least one snap-fitting member designed to cooperate with a retaining element secured to the upper wall when the tubular element is assembled with the reservoir.
 2. A lighter according to claim 1, wherein the tubular element comprises two snap-fitting members for engaging the retaining element to snap-fit the tubular element in the upper wall of the reservoir in the well.
 3. A lighter according to claim 1, wherein the upper wall is formed integral with the reservoir.
 4. A lighter according to claim 1, wherein the upper wall of the reservoir, the well and the tubular element are all in the shape of a cylinder that is circularly symmetrical.
 5. A lighter according to claim 1, wherein the tubular element and the upper wall of the reservoir in the well have relatively smooth walls.
 6. A lighter according to claim 1, further comprising an annular seal arranged between the wall and the tubular element.
 7. A lighter according to claim 6, wherein the annular seal is arranged between a radially external rim formed on the tubular element and a radially internal rim formed on the wall.
 8. A lighter according to claim 7, wherein the tubular element has a first axial distance (H₁), extending between the radially external rim and a point of contact where the snap-fitting member engages the retaining element, and the upper wall has a second axial distance (H₂) between the radially internal rim and the point of contact, the first and second distances (H₁, H₂) being chosen to exert a pre-determined pressure on the annular seal.
 9. A lighter according to claim 1, wherein the retaining element is formed on a lower portion of an interior face of the upper wall.
 10. A lighter according to claim 1, wherein the snap-fitting member is arranged in a lower part of the tubular element.
 11. A lighter according to claim 10, wherein the snap-fitting member comprises a tab having a nib, the nib being directed radially outwards and having a transverse face, the tab being elastic in a radial direction.
 12. A lighter according to claim 1, wherein the tubular element further comprises a regulating device.
 13. A lighter according to claim 12, wherein the regulating device is a microporous membrane.
 14. A lighter according to claim 13, wherein the tubular element further comprises a metal inner tube having a lowered end for receiving the microporous membrane.
 15. A lighter according to claim 1, wherein the tubular element has an upper end comprising a radially internal rim defining an opening through which there passes an outlet duct of a valve, the valve being moveable along an axis of the tubular element, wherein a compression spring is arranged between the radially internal rim and the valve.
 16. A lighter according to claim 1, wherein the reservoir is formed of a material selected from the group consisting of styrene acrylonitriles or acrylonitrile butadiene styrenes.
 17. A lighter according to claim 1, wherein the tubular element is made of semi-crystalline polymer.
 18. A gas lighter comprising: a reservoir containing a fuel, the reservoir having an upper wall, a well, the well passing through the upper wall; and a gas-dispensing device having at least one tubular element including at least one snap-fitting member; wherein the upper wall includes a retaining element for engaging the snap-fitting member.
 19. A lighter according to claim 18, wherein the tubular element comprises two snap-fitting members for engaging the retaining element to snap-fit the tubular element in the upper wall of the reservoir in the well.
 20. A lighter according to claim 18, wherein the upper wall is formed integral with the reservoir.
 21. A lighter according to claim 18, wherein the upper wall of the reservoir, the well and the tubular element are all in the shape of a cylinder that is circularly symmetrical.
 22. A lighter according to claim 18, wherein the tubular element and the upper wall of the reservoir in the well have relatively smooth walls.
 23. A lighter according to claim 18, further comprising an annular seal arranged between the upper wall and the tubular element.
 24. A lighter according to claim 23, wherein the annular seal is arranged between a radially external rim formed on the tubular element and a radially internal rim formed on the upper wall.
 25. A lighter according to claim 24, wherein the tubular element has a first axial distance (H₁), extending between the radially external rim and a point of contact where the snap-fitting member engages the retaining element, and the wall has a second axial distance (H₂) between the radially internal rim and the point of contact, the first and second distances (H₁, H₂) being chosen to exert a pre-determined pressure on the annular seal.
 26. A lighter according to claim 18, wherein the retaining element is formed on a lower portion of an interior face of the upper wall.
 27. A lighter according to claim 18, wherein the snap-fitting member is arranged in a lower part of the tubular element.
 28. A lighter according to claim 27, wherein the snap-fitting member comprises a tab having a nib, the nib being directed radially outwards and having a transverse face, the tab being elastic in a radial direction.
 29. A lighter according to claim 18, wherein the tubular element further comprises a regulating device.
 30. A lighter according to claim 29, wherein the regulating device is a microporous membrane.
 31. A lighter according to claim 30, wherein the tubular element further comprises a metal inner tube having a lowered end for receiving the microporous membrane.
 32. A lighter according to claim 18, wherein the tubular element has an upper end comprising a radially internal rim defining an opening through which there passes an outlet duct of a valve, the valve being moveable along an axis of the tubular element, wherein a compression spring is arranged between the radially internal rim and the valve.
 33. A lighter according to claim 18, wherein the reservoir is formed of a material selected from the group consisting of styrene acrylonitriles or acrylonitrile butadiene styrenes.
 34. A lighter according to claim 18, wherein the tubular element is made of semi-crystalline polymer.
 35. A method of manufacturing a gas lighter having a reservoir including an upper wall having a retaining element and a well which passes through the upper wall, the method comprising: providing a gas dispensing device within the well, the gas dispensing device including at least one tubular element having at least one snap-fitting member, wherein the step of providing a gas dispensing device within the well comprises: placing the tubular element into the well until the snap-fitting member engages the retaining element thereby securing the dispensing device into the well.
 36. The method of claim 35, wherein the tubular element comprises two snap-fitting members for engaging the retaining element.
 37. The method of claim 35, wherein the upper wall is formed integral with the reservoir.
 38. The method of claim 35, wherein the upper wall of the reservoir, the well and the tubular element are all in the shape of a cylinder that is circularly symmetrical.
 39. The method of claim 35, wherein the tubular element and the upper wall of the reservoir in the well have relatively smooth walls.
 40. The method of claim 35, further comprising providing an annular seal between the upper wall and the tubular element.
 41. The method of claim 40, wherein the annular seal is arranged between a radially external rim formed on the tubular element and a radially internal rim formed on the upper wall.
 42. The method of claim 41, wherein the tubular element has a first axial distance (H₁), extending between the radially external rim and a point of contact where the snap-fitting member engages the retaining element, and the wall has a second axial distance (H₂) between the radially internal rim and the point of contact, the first and second distances (H₁, H₂) being chosen to exert a pre-determined pressure on the annular seal.
 43. The method of claim 35, wherein the retaining element is formed on a lower portion of an interior face of the upper wall.
 44. The method of claim 35, wherein the snap-fitting member is arranged in a lower part of the tubular element.
 45. The method of claim 44, wherein the snap-fitting member comprises a tab having a nib, the nib being directed radially outwards and having a transverse face, the tab being elastic in a radial direction.
 46. The method of claim 35, wherein the tubular element further comprises a regulating device.
 47. The method of claim 46, wherein the regulating device is a microporous membrane.
 48. The method of claim 47, wherein the tubular element further comprises a metal inner tube having a lowered end for receiving the microporous membrane.
 49. The method of claim 35, wherein the tubular element has an upper end comprising a radially internal rim defining an opening through which there passes an outlet duct of a valve, the valve being moveable along an axis of the tubular element, wherein a compression spring is arranged between the radially internal rim and the valve.
 50. The method of claim 35, wherein the reservoir is formed of a material selected from the group consisting of styrene acrylonitriles or acrylonitrile butadiene styrenes.
 51. The method of claim 35, wherein the tubular element is made of semi-crystalline polymer. 